Major depressive disorder is the leading cause for disability among adolescents globally, and most young people do not receive treatment. Schools provide an unparalleled opportunity to reach early adolescents and reduce the global mental health treatment gap. Situated throughout urban and rural areas, schools are often located in communities with few-to-no other social service or health infrastructure. Growing evidence indicates that mental health treatment can be effectively delivered in low-resource schools by non-mental health professionals. However, a lack of research exists on schools-based treatment interventions for depression, especially in low and middle-income countries, or how to implement them within educational systems. This K01 proposes a multi-phase research study to implement Group Interpersonal Psychotherapy for Depressed Adolescents (IPT-G-A) in schools in Uganda. IPT-G-A is a manualized depression intervention that has demonstrated effectiveness with adolescents in Uganda, but has not yet been implemented or scaled-up in school settings. This project aims to understand the factors relevant to implementation and effectiveness of depression treatment in Ugandan schools and pilot a strategy for implementing IPT-G-A, leveraging an existing violence prevention program called the Good School Toolkit (GST). This study has three specific aims. The first aim is to examine factors relevant to the implementation and effectiveness of school-based interventions through secondary analysis of data from the GST effectiveness trial. Next, the project aims to determining the contextual and cultural influences on the implementation of IPT-G-A in schools leveraging the GST through qualitative methods. The third aim is to examine the acceptability and feasibility of implementing IPT-G-A for early adolescents with elevated internalizing symptoms through a pilot in 2 Ugandan primary schools currently using the GST. These research activities will be combined with a comprehensive training program that integrates didactic lectures and mentored experiences. Led by Primary Mentor, Dr. Myrna Weissman, the plan includes the following goals: (1) to expand knowledge about parameters that are relevant to effectiveness and implementation of mental health interventions for adolescents; (2); to develop expertise in how to improve adoption of evidence-based interventions in school-based settings using community engagement approaches and (3) to learn and apply principles of hybrid effectiveness- implementation designs. This training will support my long-term career goal to become an independent investigator in effectiveness and implementation science for global mental health with a focus on adolescence. The research plan will produce data for a R01 to conduct a Type 2 Hybrid Effectiveness- Implementation Study on IPT-G-A in Ugandan schools leveraging the GST.